A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia.
Department of Chemistry, York University, Toronto, ON M3J 1P3, Canada.
Biosensors (Basel). 2023 Sep 1;13(9):866. doi: 10.3390/bios13090866.
Lateral flow immunoassay (LFIA) has found a broad application for testing in point-of-care (POC) settings. LFIA is performed using test strips-fully integrated multimembrane assemblies containing all reagents for assay performance. Migration of liquid sample along the test strip initiates the formation of labeled immunocomplexes, which are detected visually or instrumentally. The tradeoff of LFIA's rapidity and user-friendliness is its relatively low sensitivity (high limit of detection), which restricts its applicability for detecting low-abundant targets. An increase in LFIA's sensitivity has attracted many efforts and is often considered one of the primary directions in developing immunochemical POC assays. Post-assay enhancements based on chemical reactions facilitate high sensitivity. In this critical review, we explain the performance of post-assay chemical enhancements, discuss their advantages, limitations, compared limit of detection (LOD) improvements, and required time for the enhancement procedures. We raise concerns about the performance of enhanced LFIA and discuss the bottlenecks in the existing experiments. Finally, we suggest the experimental workflow for step-by-step development and validation of enhanced LFIA. This review summarizes the state-of-art of LFIA with chemical enhancement, offers ways to overcome existing limitations, and discusses future outlooks for highly sensitive testing in POC conditions.
侧向流动免疫分析（LFIA）已在即时检测（POC）环境中得到广泛应用。LFIA 使用测试条进行操作，这些测试条是完全集成的多膜组件，包含用于分析性能的所有试剂。液体样本沿测试条迁移，启动标记免疫复合物的形成，这些复合物可通过肉眼或仪器进行检测。LFIA 的快速性和易用性的权衡是其相对较低的灵敏度（高检测限），这限制了其用于检测低丰度靶标的适用性。提高 LFIA 的灵敏度引起了许多关注，通常被认为是开发免疫化学 POC 分析的主要方向之一。基于化学反应的后分析增强有助于提高灵敏度。在这篇重要的综述中，我们解释了后分析化学增强的性能，讨论了它们的优点、局限性、与检测限（LOD）改进的比较，以及增强程序所需的时间。我们对增强 LFIA 的性能提出了关注，并讨论了现有实验中的瓶颈。最后，我们提出了用于增强 LFIA 的逐步开发和验证的实验工作流程。该综述总结了 LFIA 与化学增强的最新技术，提供了克服现有局限性的方法，并讨论了在 POC 条件下进行高灵敏度检测的未来展望。
